There are certain medical procedures that are carried out within a body cavity. One example of such a procedure is tissue ablation. Ablation of the interior lining of a body organ is a procedure which involves heating the organ lining to temperatures which destroy the cells of the lining or coagulate tissue proteins. Such a procedure may be performed as a treatment to one of many conditions, such as chronic bleeding of the endometrial layer of the uterus or abnormalities of the mucosal layer of the gallbladder. Existing methods for effecting ablation include circulation of heated fluid inside the organ (either directly or inside a balloon), laser treatment of the organ lining, and resistive heating using application of RF energy to the tissue to be ablated.
Ablation procedures are often carried out without direct endoscopic visualization. For example, ablation of the endometrium typically involves insertion of an elongate ablation device into the patient's cervix without the use of a hysteroscope. As can be appreciated, the presence of a perforation in the uterus could result in inadvertent passage of the ablation device through the perforation and out of the uterus into the bowel. Although events of this nature are rare, the injury that could result from such occurrences make it highly desirable to provide a mechanism by which a physician can evaluate whether perforations are present in a body cavity before a treatment device such as an ablation device is used to deliver power.